Electric power transmission.



J. G. P. THOMAS.

ELECTRIC POWER TRANSMISSION.

APPLICATION FILED JUNE 26, I913.

Patented Feb. 27, 1917.

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JOHN GODFREY PARRY THOMAS, 0F CI-IISVFIGK, LONDQN, ENGLAND, ASSIGNOR TOTHOMAS FOREIGN PATENTS LIMITED, (1F LONDON, ENGLAND, A CORPORATION OFGREAT BRITAIN.

Application filed June 26, 1913.

To all whom it may concern.

Be it known that I, J OHN GODFREY PARRY THOMAS, a subject 'of the Kingof Great Britain, residing at 21 Ennismore avenue, Chiswick, in thecounty of London, England, have invented new and useful Tmprovements inElectric Power Transmission, of which the following is a specification.

This invention relates to electromechanical power transmission systemsin which a prime motor is joined through a balance or epicyclic gear totwo dynamo electric machines one of which is upon the driven shaft. Itis especially concerned with an improved mechanical disposition of suchmachines which facilitates their mounting, for instance in a vehicle,and obviates many seri ous difficulties in alining the separate shafts.The new arrangement also enables the clutches requisite for theoperation of the system to be disposed in a more advantageous manner.The invention further relates to means for interconnecting thoseclutches with the electrical control apparatus so that the clutches maybe controlled by a single clutch pedal or lever but come into engagementonly when the electrical conditions of the machine are appropriate tosuch engagement.

In the accompanying drawings Figure 1 shows in half cross sectionalele-- vation a construction embodying the invention, while Fig. 2illustrates diagrammatically the interconnection of the clutches of Fig.1 with the electrical control mechanism.

Fig. 3 is a plan of an alternative construction of a part of Fig. 2.

Fig. a illustrates a modification of the arrangement shown in Fig. 2.

In the drawings, 1 is the shaft driven by a prime motor (not shown) andthis carries a fly wheel 2 of ordinary form. A flexible coupling of anysuitable type shown conventionally at 2 connects this fly wheel with thedrum 3 upon a shaft 4- whieh at its other end is connected with thecentral web 5 of a casing 6 in which are supported pairs of planetpinions 7, 8. These mesh respectively with sun pinions 9, 10 the formerof which is keyed upon a sleeve 11 surrounding the shaft & and carryingat 12 the armature of a dynamo electric machine.-

The further end of the armature rests upon a sleeve 13 also surroundingthe shaft 4:

Specification of Letters Patent.

Patented Feb. 27, 1917.

Serial No. 775,949.

and having keyed to it one member of an expanding or other frictionclutch 1 1 which when in action joins the sleeve to the drum 3 keyedupon the shaft 1, thereby rendering the epicyclic gear 7, S, 9, 1Oinoperative. The sun wheel 10 is keyed to the outer member 15 of asimilar friction clutch, the inner member of which is upon a shaft 16which carries at 17 the armature of a sec 011d dynamo electric machine,and which is joined directly, or in the case of vehicles through auniversal coupling, to the load shaft.

The whole of this structure from the flexible coupling between the flywheel 2 and drum 3 to the universal coupling between the shaft 17 andthe road wheels is supported in a frame built up from the casings of theelectrical machines. These casings 18 and 19 have end plates supportingbearings for the respective shafts with which they make oil-tightjoints. The casing 18 is extended at 20 to partially inclose theepicyclic gearing and is rigidly joined by a bolted-on tubular section21 to the casing 19. This combined casing is very readily suspended in avehicle frame by suitable saddles.

By means of: electrical connections between the machines 12 and 17 andcontrol apparatus therefor, not illustrated in the drawingsbut now wellknown, this mechanism can be employed to transmit from the substantiallyconstant speed shaft 1 a variable speed drive to the load shaft 16.

The clutch 1 1 requires to be in action only when the vehicle is runningon top speed, when by locking the gear it renders the power transmissionpurely mechanical; or when the engine is being started by the aid of theelectrical machine 12; or, finally, when the vehicle is being drivenbackward by the aid of the machine 12 driven as a generator andactuating the machine 17 purely electrically as a motor. The clutch 15on the other hand, requires to be in action at all times except when itis desired to run the engine free or in starting or reversing. Theseclutches are conveniently disengaged or heldout of action by the use ofa foot pedal 22, as illustrated diagrammatically in Fig.2. The pedalrotates a shaft 27 to which are attached cranks 28 and 29 joined by rods30 and 31 respectively to levers 32, 33 by which the respective clutches15 and 14: are moved. But the connec n between the rods 30 and 31 andthe lovers 32 and is not rigid. In the con struction of Fig. 2 the endsof the levers 32 and 33 are slotted as at 34:, 35 and the slots receivepins on the ends of the respective levers 30 and 31. This makes itpossible for either clutch to remain disengaged when the other isallowed to engage. In order that the clutches may not be allowed toreengage under the action of their own springs at inappropriate moments,they are suitably interconnected with the electrical controller so as tobe held out independently of the pedal 22 when they should not beengaged. In the diagram illustrated in Fig. 2 each clutch operatinglever 32, 33 is joined through links 36, 37 to a bell crank lever l3, 23pivoted adjacent to the disks 2 1, 25 which are fast on the shaft 38 ofthe electrical controller. These disks are provided with cam projections26 which are in position to engage with the respective levers 43, 23upon rotation of the controller and when so engaged prevent therespective clutches coming into operation.

It is not necessary that the mere rotation of the controller shouldbring the clutches out of action though the cam 00- acting with lever 23is shown at 39 (in Fig. 2) as adapted to permit this. It is preferableto have the top speed clutch disengaged by a solenoid or otherelectrical operating de vice which is brought into action by suitablecontacts on the controller; this greatly lessens the muscular effortrequired for the operation of the controller. Such apparatus isindicated in dotted lines in Fig. 4:. 10 indicates the core of asolenoid which is joined to the rod 37 so that when attracted throughthe excitation of the solenoid the clutch 1 will be operated and thelever 23 lifted so as to permit the passage of its cam 26 beneath it. Inthis case the cam may have a radial instead of a sloping edge asindicated at 4:1. The winding 42 of the solenoid is connected with asuitable battery as and with contacts 4-5 in the controller, which arebridged at the proper instant by a contact member 46 on the controllershaft.

This interconnection of the clutches with the controller enables thevehicle to be readily driven backward by putting the controller in thereverse position and locking the gear for as long as is necessary bymeans of the clutch 14. In actual operation having once put thecontroller in the reverse position the driver will move the vehiclebackward and stop it as he desires by putting the clutch in or out.

It will be obvious that mechanical equivalents may replace thepin-and-slot connec tions which permit independent motion of theclutches. For instance as shown in Fig. 3 the clutch pedal 22 may have anotched boss 4L7 loosely rotatable on the shaft 27 and each of thecranks 28, 29 may have a similar notched boss adapted to engage withboss l? as shown. Thus depression of the pedal will cause the rotationof both cranks, whereas when the pedal is released the cranks need notfollow it. It will be understood that if the construction of Fig. 3 isadopted the pin-and-slot connections 34, 35 will be dispensed with and asimple pin connection substituted.

hat I claim is:

1. In an electric power transmission system the combination with twodynamo electric machines of means rigidly connecting their stationaryparts, a driving shaft coaxial with and passing through the shaft of oneof said machines, pairs of planet pinions of different size carried bysaid driving shaft, sun wheels of different size inter-meshing with saidplanet wheels and connected with respective dynamo shafts, and a clutchadapted to join said driving shaft with the dynamo shaft carrying thesmall sun wheel.

2. In an electromechanical power transmission system, the combinationwith two dynamo electric machines of means rigidly connecting theirstationary members so as to form a rigid casing, bearings in said casingsupporting the shaft of said machines coaxially, a driving shaftcontained within one of said shafts, pairs of planet pinions car ried bysaid driving shaft intermediate said machines, a sun pinion on onedynamo shaft meshing with one set of planet pinions, a sun pinionmeshing with the other set of planet pinions, a fourth stub shaftcarrying said latter sun pinion, a clutch member upon said stub shaftand a co-action clutch member upon the remaining dynamo shaft alsointermediate said dynamos.

3. In an electromechanical power transmission system the combinationwith two dynamo electric machines of a rigid casing formed from theirstationary members sup porting their shafts co-aXially, a driving shaft,a balance gear adapted to interconnect said driving shaft with saiddynamos, a clutch for rendering said balance gear inoperative, a clutchfor separating one of said dynamo shafts from said gearing, and a clutchoperating member adapted to hold both of said clutches out ofengagement.

4. In an electromechanical power transmission system the combinationwith two dynamo electric machines of a driving shaft, a balance gearinterconnecting said shaft with the shafts of said dynamos, a clutchrendering said balance gear inoperative, a second clutch for separatingone of said dynamo shafts from said gear, a single clutch operatingmember adapted to hold both of said clutches out of operation, acontroller for said dynamo electric machines, and means on saidcontroller for preventing each of said clutches coming into operation iiparticular positions of the controller.

5. In an electromechanical power trans mission system the combinationwith two dynamo electric machines of a driving shaft, a balance gearinterconnecting said shaft with the shafts of said dynamos, a clutchrendering said balance gear inoperative, a second clutch for separatingone of said dynamo shafts from said gear, a single clutch operatingmember adapted to hold both of said clutches out of operation, acontroller for said dynamo electric machines,

means on said controller for preventing each of said clutches cominginto operation in particular positions of the controller, and furthermeans on said controller for operating electrically the clutch whichrenders the balance gear inoperative.

In testimony whereof I have signedmy name to this specification in thepresence of two subscribing witnesses.

JOHN GODFREY PARRY THOMAS.

WVitnesses A. E. ODELL,

LEONARD E. HAEFNER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

